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Periodically, questions arise regarding malfunctioning gauges in their Ford. Not surprising since many are over sixty years old.
History: Ford purchased their gauges and sending units from King-Seeley since Model T days, or maybe before. Ford (and other manufacturers) used these gauges in all their cars and trucks. Electrical systems were six volts and simple, so gauges and ignition systems needed no CVRs or ballast resistors. Ford transitioned to twelve volts, including gauges in 1956, which caused problems. Ford quickly reverted back to six-volt gauges and ignition systems in 1957, and kept that scheme for many decades.
Operation: For 1957, King-Seeley manufactured an 'add-on' CVR to their 6-volt gauges that inputs 12-volts but cycles it on-and-off at 50% duty cycle. That allowed half the current to flow through the gauges, giving an AVERAGE current equal to 6-volts. The gauges use ni-chrome wire with high resistance that creates heat in direct proportion to the current flowing through it. The gauge needle is attached to a bi-metal strip, wrapped in ni-chrome wire, which causes deflection, much like old house thermostats. This system is nearly bullet proof because there are no bearings or armatures and polarity can be in either direction. Temp and Fuel gauges are identical inside.
The best way to describe problems with your gauge system is by citing a real-life example from a member who went through his system and fixed his gauges...
-----Original Message-----
From: 'SB Member'
To: <simplyconnected@aol.com>
Sent: Feb 12, 2018 8:49am
Subject: CVR
Hi Dave,
Are you still in the business of making 6 volt CVRs?
I have a '63 Fairlane and (long story short) it seems that the 5 volt CVRs
available from other sellers are not quite doing the job.
I'd like to try a 6 volt CVR, or find one that is adjustable between
5 and 6 volts.
Thnx!
'SB Member'
On Feb 12, 2018, at 6:26 AM, Dave <simplyconnected@aol.com> wrote:
'SB Member', I am doing retrofits, meaning, I take OEM CVRs, gut them then I replace the mechanical contacts and bi-metal strips with a fixed six volt solid state regulator.
Do you have a solid instrument panel ground? The ground is equally important as the +12 side. Never run a CVR unless it is screwed to a grounded surface.
My regulators output a rock steady six volts because that is what your gauges are made for. In 1956, Ford went with the 12-volt system, including gauges. In '57, Ford quickly reverted all gauges to work using an 'average 6-volts' meaning, they added a CVR that cycles on/off at 50% duty cycle (like a flasher unit) which offers an average of 6-volt current to the gauge and sending unit. After many years, when those CVRs fail they usually get erratic, the contacts stick shut or the contacts simply open. Mine don't pulse.
Tell me what problems you are having with your gauges and what tests you have done. - Dave
From: 'SB Member'
To: Dave <simplyconnected@aol.com>
Sent: Mon, Feb 12, 2018 8:13 pm
Subject: Re: CVR
Aaaah Dave, at last the voice of reason. Someone else who understands that my gauges need more than 5 volts!
So, I am going to spare you a lot of the gory details (I am sure you have heard it all before). My setup is a '63 Fairlane that has spent most of its life in a garage. At present it has the original stock sender in the tank, which I carefully cleaned and bench tested. New float that I checked for holes. New filter sock. New gas tank that looks identical to the original, except they painted the outside with clear coat (not thrilled about that). Gauges are original. Instrument cluster is grounded directly to the block where the negative battery cable is bolted on. Sender is grounded to the frame via a wire from the outlet tube to a bolt on the frame. I have experimented with grounding both the tank and the sender directly to the negative battery terminal with no change in the gauge reading, which tells me that the ground wire I installed from the sender to the frame is doing the job. Tank is full up into the spout, but gauge needle is sitting just below and next to the full mark. I have also tried running the car at high idle for a few minutes with no change in the gauge.
Here are the problems I have observed: Right now I am getting 13 ohms of resistance on the sender measured on the sender wire post under the car. That's
a bit on the high side, but I see no way of improving that. The float is at the top of its range, and if I try to mess with the windings inside the rheostat or the
wiper I will almost certainly make the resistance problem worse! I did clean out the rheostat with electric cleaner spray and a very soft small paintbrush. It
was in good condition, nothing broken, no corrosion. It has the 'wine glass-shaped' windings… so practically impossible to replace.
I took off the CVR, which from all appearances is the original one, and tested it with a volt meter. I got 12v steady on a digital voltmeter. Opened it up and
the points were badly pitted and caked with carbon, so it was worn out. Ordered a CVR from Melvin's. Tested it and it is a solid state unit with a steady
5 volts of output. Installed it on the car, and my gauge does not move to where it should be. From all the reading I have done, the factory CVR would
yield an average output closer to 6v, just like you said, by pulsing between 0v and 10v.
Today I did some further testing on the car. I noticed that my gauge is a bit sticky between 3/4 and full when connected to a 3 volt power source (tested
according to directions in the shop manual). Needle slows way down when it gets to 3/4, then crawls up to sit next to the full mark. Then I connected the sender wire to the gauge, and a DC power supply to the gauge on the post normally connected to the CVR. Gave it 4.5 volts, and gauge did the same ol' thing, moved up next to full and sat there. I wanted to see if 6 volts would overcome the slightly high resistance of the sender, so I gave it 6 volts DC and the gauge went exactly to where It should be, above full, about half way between the full mark and what you would consider 'pegged out.' So, yes. In my case, 6 volts does overcome the slightly sticky old gauge and the slightly funky old sender. Weeeeeeeeeeeee!
Can you remake the 'weak' 5 volt CVR that Melvin's sold me into a 6 volt CVR? It looks a lot like the original, but with no calibration post. My original one got kinda messed up when I ripped into it to see what was going on. What do you charge for rebuilding?
Thank you!
~ 'SB Member'
_______
_/________\_
(O)----|=|----(O)
\__________/
...|_|............|_|...
From: 'SB Member'
To: Dave <simplyconnected@aol.com>
Sent: Tue, Feb 13, 2018 5:49 pm
Subject: Re: CVR
Hi Dave!
On Feb 13, 2018, at 10:40 AM, Dave <simplyconnected@aol.com> wrote:
Yep! Knew about the heated wire moving the needle, etc.
I'm a little vague on how your instrument panel gets its ground from the block. Most modern cars use a short #10AWG wire connecting the battery (NEG) to the car's body and the main ground connects to the engine. For my classic cars, I ground the body and continue the unbroken wire to an area close to the starter motor (which draws the most current by far). I also run a separate ground wire from the battery to the trunk, tapping off along the way for the instrument panel, power doors & seats, convertible top pump motor, trunk light, fuel sending unit, taillight & license plate housings and any trailer or inverter connections. Modern cars do not depend on steel body spot welds to carry ground and I don't either. Modern lamp sockets also have a separate ground wire in their connector so rear lights cannot dance back and forth when the brake is applied.
I installed a ground Dave, just a couple of weeks ago, just as a safety measure. Originally the cluster just grounded thru the mounting screws that attached it to the dash. My ground attaches to the bolt on the engine block where the negative battery cable is bolted on. From there I ran it around the engine compartment, thru the firewall, under the dash, and finally attached it to the steel back of the instrument cluster with a sheet metal screw. Wanted to be sure my gauges were protected, now and in the future!
Your OEM CVR is adjusted to pulse 12-volts at 50% duty cycle which cuts the current in half, giving an average current from six volts. A Fluke meter with a frequency setting will show this. If your meter also has a delta (change-in) setting, the display will show how erratic the pulse is.
I tested the new one I got from Mxxxxx's with a digital voltmeter after grounding it and connecting it to the car battery. It converts the 12v to a steady, non-pulsing 5 volts. They also told me theirs are solid state 5 volt, so that matches my findings.
You can simulate my CVR by using four AA batteries in series to supply power to your gauges (assuming they are connected to their sending units). Less than six volts isn't enough.
Right on! That is what I found too! Makes perfect sense. They are, after all, SIX VOLT gauges. ( : # I did some testing using an adjustable DC power supply/converter. It's a switch box you can plug into the lighter and switch the voltage to different settings. I tested my gauge and sender setup with 3, 4.5, and 6 volts (no higher). At 6 volts it functioned perfectly.
All this is foreign to most restorers but I'm a retired Ford Motor Company Electrical Engineer so it comes as second nature to me. Because the King-Seeley gauges (yep, Ford bought them) are so simple, they last nearly forever.
Okay, you are officially like the coolest person I know now! I have just a 'smattering' of electrical knowledge due to having worked for Hewlett-Packard in the 1990s. Hey! Maybe you can answer a couple of questions for me… or maybe give a short description?
I have been wondering during this troubleshooting process how these senders, regulator, gauge installs were originally done in the Ford factory. Did they make all the senders identical; then attach the CVR and gauges to the sender and calibrate them; then install on the car?
Also, how were the senders grounded? I think they were grounded on the alignment tangs where they fit to the opening of the tank. One guy with a '62 Fairlane has been trying to convince me that the gas tank was isolated from the trunk floor and mounting straps by foam rubber and rubber bumpers (not grounded to the frame). On my '63 Fairlane the tank was definitely grounded to the frame!
CVRs, Gauges and Sending units all came to Ford 'pre-adjusted' and are identical. The gauges and CVRs were 'set' at the King-Seeley factory. There is no adjustment for the Temp sending unit. The Fuel sending unit has a float arm that may be bent to adjust for 'bottom of the tank'. The fuel arm length determines the range. You may read this thread to find the particulars: https://squarebirds.org/vbulletin/showthread.php?t=14869
I am the Webmaster at Squarebirds.org. I promote all T-bird owners to become paid members by offering them a sweet deal for helping us out regardless of the year of their Ford.
I would like your original CVR if you have it. If it's too messed up call me at (248) 544-8834. I'm just north of Detroit. - DaveI have three CVRs. The new one looks just like the original--I have not messed up the case on that one. Plus, I have two other burned out ones. One was from another Fairlane, and the other is the one I just pulled off my car. I opened them with 'nippers' carefully, but as I did so the tangs got sorta bent up and scratched. I could send you the nice one and one of the burned-out ones, if you like. It is 'your call' as to whether or not they are too messed up.
Could I please have your mailing address and I will send them to you? Not asking for any special deal here, just a fair deal on a unit that puts out 6 volts. If not from you, then I will probably buy a Motorcraft NOS CVR on ebay. They go for about $50. nowadays.
Thanks so much for getting back to me!
'SB Member'
Hi 'SB Member',
You have to think in terms of 'production' where everything is done in under a minute. Ford did not make the gauges or CVRs. King-Seeley made them and Ford simply screwed them to the instrument panel.
Instrument panels are made in an off-line sub-assembly because there are so many options. The I.P. line started with racks of bare dashboards in different colors. The assemblers secured each to a moving trunnion so the dash could be rotated. Wire harnesses for power window options. radio options and brake pedal supports were added to suit each build sheet as the car they were to be installed in are so far down the Trim Line they cannot be seen (yet). About every fourth car was a convertible so their dash lights were different (there is no dome light). Some cars had no radio. Some went to Arab countries so they got no heater. Some were stick shift so their brake pedal support had clutch and brake pedals, etc.
Gauges and CVRs were manufactured and calibrated at King-Seeley, not at Ford. Temp and Fuel sending units have no adjustments.
I sell my solid state CVR to non-paid members for $35 plus $7 US shipping, (including domestic insurance). But if you become a Paid Member of Squarebirds.org, you can buy it for $25+ $7. I also need an old CVR to retrofit. I don't care if the core works as long as the case is ok.
Send your core and check to:
Dave Dare
2112 N. Vermont Ave.
Royal Oak, MI 48073-2402
Disclaimer: These emails were current in Feb., 2018. Prices have changed so message me for current status.
Please post questions or concerns. - Dave
History: Ford purchased their gauges and sending units from King-Seeley since Model T days, or maybe before. Ford (and other manufacturers) used these gauges in all their cars and trucks. Electrical systems were six volts and simple, so gauges and ignition systems needed no CVRs or ballast resistors. Ford transitioned to twelve volts, including gauges in 1956, which caused problems. Ford quickly reverted back to six-volt gauges and ignition systems in 1957, and kept that scheme for many decades.
Operation: For 1957, King-Seeley manufactured an 'add-on' CVR to their 6-volt gauges that inputs 12-volts but cycles it on-and-off at 50% duty cycle. That allowed half the current to flow through the gauges, giving an AVERAGE current equal to 6-volts. The gauges use ni-chrome wire with high resistance that creates heat in direct proportion to the current flowing through it. The gauge needle is attached to a bi-metal strip, wrapped in ni-chrome wire, which causes deflection, much like old house thermostats. This system is nearly bullet proof because there are no bearings or armatures and polarity can be in either direction. Temp and Fuel gauges are identical inside.
The best way to describe problems with your gauge system is by citing a real-life example from a member who went through his system and fixed his gauges...
-----Original Message-----
From: 'SB Member'
To: <simplyconnected@aol.com>
Sent: Feb 12, 2018 8:49am
Subject: CVR
Hi Dave,
Are you still in the business of making 6 volt CVRs?
I have a '63 Fairlane and (long story short) it seems that the 5 volt CVRs
available from other sellers are not quite doing the job.
I'd like to try a 6 volt CVR, or find one that is adjustable between
5 and 6 volts.
Thnx!
'SB Member'
On Feb 12, 2018, at 6:26 AM, Dave <simplyconnected@aol.com> wrote:
'SB Member', I am doing retrofits, meaning, I take OEM CVRs, gut them then I replace the mechanical contacts and bi-metal strips with a fixed six volt solid state regulator.
Do you have a solid instrument panel ground? The ground is equally important as the +12 side. Never run a CVR unless it is screwed to a grounded surface.
My regulators output a rock steady six volts because that is what your gauges are made for. In 1956, Ford went with the 12-volt system, including gauges. In '57, Ford quickly reverted all gauges to work using an 'average 6-volts' meaning, they added a CVR that cycles on/off at 50% duty cycle (like a flasher unit) which offers an average of 6-volt current to the gauge and sending unit. After many years, when those CVRs fail they usually get erratic, the contacts stick shut or the contacts simply open. Mine don't pulse.
Tell me what problems you are having with your gauges and what tests you have done. - Dave
From: 'SB Member'
To: Dave <simplyconnected@aol.com>
Sent: Mon, Feb 12, 2018 8:13 pm
Subject: Re: CVR
Aaaah Dave, at last the voice of reason. Someone else who understands that my gauges need more than 5 volts!
So, I am going to spare you a lot of the gory details (I am sure you have heard it all before). My setup is a '63 Fairlane that has spent most of its life in a garage. At present it has the original stock sender in the tank, which I carefully cleaned and bench tested. New float that I checked for holes. New filter sock. New gas tank that looks identical to the original, except they painted the outside with clear coat (not thrilled about that). Gauges are original. Instrument cluster is grounded directly to the block where the negative battery cable is bolted on. Sender is grounded to the frame via a wire from the outlet tube to a bolt on the frame. I have experimented with grounding both the tank and the sender directly to the negative battery terminal with no change in the gauge reading, which tells me that the ground wire I installed from the sender to the frame is doing the job. Tank is full up into the spout, but gauge needle is sitting just below and next to the full mark. I have also tried running the car at high idle for a few minutes with no change in the gauge.
Here are the problems I have observed: Right now I am getting 13 ohms of resistance on the sender measured on the sender wire post under the car. That's
a bit on the high side, but I see no way of improving that. The float is at the top of its range, and if I try to mess with the windings inside the rheostat or the
wiper I will almost certainly make the resistance problem worse! I did clean out the rheostat with electric cleaner spray and a very soft small paintbrush. It
was in good condition, nothing broken, no corrosion. It has the 'wine glass-shaped' windings… so practically impossible to replace.
I took off the CVR, which from all appearances is the original one, and tested it with a volt meter. I got 12v steady on a digital voltmeter. Opened it up and
the points were badly pitted and caked with carbon, so it was worn out. Ordered a CVR from Melvin's. Tested it and it is a solid state unit with a steady
5 volts of output. Installed it on the car, and my gauge does not move to where it should be. From all the reading I have done, the factory CVR would
yield an average output closer to 6v, just like you said, by pulsing between 0v and 10v.
Today I did some further testing on the car. I noticed that my gauge is a bit sticky between 3/4 and full when connected to a 3 volt power source (tested
according to directions in the shop manual). Needle slows way down when it gets to 3/4, then crawls up to sit next to the full mark. Then I connected the sender wire to the gauge, and a DC power supply to the gauge on the post normally connected to the CVR. Gave it 4.5 volts, and gauge did the same ol' thing, moved up next to full and sat there. I wanted to see if 6 volts would overcome the slightly high resistance of the sender, so I gave it 6 volts DC and the gauge went exactly to where It should be, above full, about half way between the full mark and what you would consider 'pegged out.' So, yes. In my case, 6 volts does overcome the slightly sticky old gauge and the slightly funky old sender. Weeeeeeeeeeeee!
Can you remake the 'weak' 5 volt CVR that Melvin's sold me into a 6 volt CVR? It looks a lot like the original, but with no calibration post. My original one got kinda messed up when I ripped into it to see what was going on. What do you charge for rebuilding?
Thank you!
~ 'SB Member'
_______
_/________\_
(O)----|=|----(O)
\__________/
...|_|............|_|...
From: 'SB Member'
To: Dave <simplyconnected@aol.com>
Sent: Tue, Feb 13, 2018 5:49 pm
Subject: Re: CVR
Hi Dave!
On Feb 13, 2018, at 10:40 AM, Dave <simplyconnected@aol.com> wrote:
Thank you for the test results Mel, I appreciate that. This information will probably make better sense of your gauge system.
Your gauges are not motors. They have no armature and no bearings. They have nothing to do with magnetism at all. Instead, they work from heat applied to a bi-metal strip, much the same as old house thermostats, your old mechanical CVR and your turn signal flasher unit.
As such, your gauges are NOT polarity sensitive because CURRENT through a ni-chrome wire creates the heat applied to the bi-metal strip. The gauges are in a confined space so very little air flow. In cold winter, they tend to read low and in hot summer, they tend to indicate on the high side. Your sending units have an effective resistance of 10-ohms to 100-ohms which limits current through the gauge. Inside, your gauges are identical and yes, you can swap the wires for testing purposes, from let's say your temp gauge to your fuel gauge.
Your gauges are not motors. They have no armature and no bearings. They have nothing to do with magnetism at all. Instead, they work from heat applied to a bi-metal strip, much the same as old house thermostats, your old mechanical CVR and your turn signal flasher unit.
As such, your gauges are NOT polarity sensitive because CURRENT through a ni-chrome wire creates the heat applied to the bi-metal strip. The gauges are in a confined space so very little air flow. In cold winter, they tend to read low and in hot summer, they tend to indicate on the high side. Your sending units have an effective resistance of 10-ohms to 100-ohms which limits current through the gauge. Inside, your gauges are identical and yes, you can swap the wires for testing purposes, from let's say your temp gauge to your fuel gauge.
Yep! Knew about the heated wire moving the needle, etc.
I'm a little vague on how your instrument panel gets its ground from the block. Most modern cars use a short #10AWG wire connecting the battery (NEG) to the car's body and the main ground connects to the engine. For my classic cars, I ground the body and continue the unbroken wire to an area close to the starter motor (which draws the most current by far). I also run a separate ground wire from the battery to the trunk, tapping off along the way for the instrument panel, power doors & seats, convertible top pump motor, trunk light, fuel sending unit, taillight & license plate housings and any trailer or inverter connections. Modern cars do not depend on steel body spot welds to carry ground and I don't either. Modern lamp sockets also have a separate ground wire in their connector so rear lights cannot dance back and forth when the brake is applied.
I installed a ground Dave, just a couple of weeks ago, just as a safety measure. Originally the cluster just grounded thru the mounting screws that attached it to the dash. My ground attaches to the bolt on the engine block where the negative battery cable is bolted on. From there I ran it around the engine compartment, thru the firewall, under the dash, and finally attached it to the steel back of the instrument cluster with a sheet metal screw. Wanted to be sure my gauges were protected, now and in the future!
Your OEM CVR is adjusted to pulse 12-volts at 50% duty cycle which cuts the current in half, giving an average current from six volts. A Fluke meter with a frequency setting will show this. If your meter also has a delta (change-in) setting, the display will show how erratic the pulse is.
I tested the new one I got from Mxxxxx's with a digital voltmeter after grounding it and connecting it to the car battery. It converts the 12v to a steady, non-pulsing 5 volts. They also told me theirs are solid state 5 volt, so that matches my findings.
You can simulate my CVR by using four AA batteries in series to supply power to your gauges (assuming they are connected to their sending units). Less than six volts isn't enough.
Right on! That is what I found too! Makes perfect sense. They are, after all, SIX VOLT gauges. ( : # I did some testing using an adjustable DC power supply/converter. It's a switch box you can plug into the lighter and switch the voltage to different settings. I tested my gauge and sender setup with 3, 4.5, and 6 volts (no higher). At 6 volts it functioned perfectly.
All this is foreign to most restorers but I'm a retired Ford Motor Company Electrical Engineer so it comes as second nature to me. Because the King-Seeley gauges (yep, Ford bought them) are so simple, they last nearly forever.
Okay, you are officially like the coolest person I know now! I have just a 'smattering' of electrical knowledge due to having worked for Hewlett-Packard in the 1990s. Hey! Maybe you can answer a couple of questions for me… or maybe give a short description?
I have been wondering during this troubleshooting process how these senders, regulator, gauge installs were originally done in the Ford factory. Did they make all the senders identical; then attach the CVR and gauges to the sender and calibrate them; then install on the car?
Also, how were the senders grounded? I think they were grounded on the alignment tangs where they fit to the opening of the tank. One guy with a '62 Fairlane has been trying to convince me that the gas tank was isolated from the trunk floor and mounting straps by foam rubber and rubber bumpers (not grounded to the frame). On my '63 Fairlane the tank was definitely grounded to the frame!
CVRs, Gauges and Sending units all came to Ford 'pre-adjusted' and are identical. The gauges and CVRs were 'set' at the King-Seeley factory. There is no adjustment for the Temp sending unit. The Fuel sending unit has a float arm that may be bent to adjust for 'bottom of the tank'. The fuel arm length determines the range. You may read this thread to find the particulars: https://squarebirds.org/vbulletin/showthread.php?t=14869
I am the Webmaster at Squarebirds.org. I promote all T-bird owners to become paid members by offering them a sweet deal for helping us out regardless of the year of their Ford.
I would like your original CVR if you have it. If it's too messed up call me at (248) 544-8834. I'm just north of Detroit. - Dave
Could I please have your mailing address and I will send them to you? Not asking for any special deal here, just a fair deal on a unit that puts out 6 volts. If not from you, then I will probably buy a Motorcraft NOS CVR on ebay. They go for about $50. nowadays.
Thanks so much for getting back to me!
'SB Member'
Hi 'SB Member',
You have to think in terms of 'production' where everything is done in under a minute. Ford did not make the gauges or CVRs. King-Seeley made them and Ford simply screwed them to the instrument panel.
Instrument panels are made in an off-line sub-assembly because there are so many options. The I.P. line started with racks of bare dashboards in different colors. The assemblers secured each to a moving trunnion so the dash could be rotated. Wire harnesses for power window options. radio options and brake pedal supports were added to suit each build sheet as the car they were to be installed in are so far down the Trim Line they cannot be seen (yet). About every fourth car was a convertible so their dash lights were different (there is no dome light). Some cars had no radio. Some went to Arab countries so they got no heater. Some were stick shift so their brake pedal support had clutch and brake pedals, etc.
Gauges and CVRs were manufactured and calibrated at King-Seeley, not at Ford. Temp and Fuel sending units have no adjustments.
I sell my solid state CVR to non-paid members for $35 plus $7 US shipping, (including domestic insurance). But if you become a Paid Member of Squarebirds.org, you can buy it for $25+ $7. I also need an old CVR to retrofit. I don't care if the core works as long as the case is ok.
Send your core and check to:
Dave Dare
2112 N. Vermont Ave.
Royal Oak, MI 48073-2402
Disclaimer: These emails were current in Feb., 2018. Prices have changed so message me for current status.
Please post questions or concerns. - Dave
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